1. Field of the Invention
This invention relates to a seal device of a high pressure steamer adapted for dyeing a cloth material.
2. Description of the Prior Art
Generally, cloth materials are dyed by immersing them in hot water or by subjecting them to a steaming process after a dye is applied to them. Heretofore, after dye is applied to a cloth material to be dyed by passing the cloth material through a dye solution tank, for example, the cloth material is subjected to a hygro-thermic treatment carried out within a steamer at a temperature not exceeding 100.degree. C. for color development. Accordingly, the conventional dyeing method has necessitated the use of a dye solution applying tank, a vat steamer and a washing tank. This requires a great amount of installation cost and a large space for installation. Besides, in accordance with the conventional method of carrying out a dyeing process at a temperature not exceeding 100.degree. C., a long period of time is required and is thus not economical.
In an effort to shorten the period of time required for dyeing, the present inventors have long conducted researches for a high speed dyeing process. As a result of this effort, they have developed a high pressure steamer which is capable of dyeing a cloth material within a short period of time in the order of seconds and is presently in actual services. In the case of dyeing with this high pressure steamer, the temperature of the humid heat within the high pressure steamer can be raised up to 170.degree. C. or thereabout to carry out dyeing a cloth material in such a short period of time. However, the high pressure steamer has a large size requiring a large space for installation and is expensive. Besides, in starting up the operation of the high pressure steamer, the temperature and the pressure within the steamer must be raised up to predetermined values, which cannot be reached in a short period of time. Thus, the high pressure steamer takes a long period of time for preparation before start-up.
Further, in order to raise the temperature within the steamer up to 170.degree. C., the high pressure humid heat within the steamer is maintained by supplying air pressure to the seal device of the steamer to have the air pressure counteract the pressurized steam contained in the inside of the steamer. However, with the air pressure used for this purpose, a portion of the air pressure mixes with the steam within the steamer. Accordingly, in cases where a color is to be developed with a threne or indanthrene dye, the dye fixing effect of a reducing agent employed is lowered by the air or oxygen thus mixed in the steam within the steamer. Further, such a reducing agent does not effectively bring forth color development at a high temperature exceeding 120.degree. C. The present invention is directed to the solution of these problems of the prior art.